U.S. Pat. No. 4,876,577, Ogura et al, issued Oct. 24, 1989, shows an electrophotographic apparatus which receives a cartridge containing a photoconductive drum. The cartridge includes both a charging mechanism for charging the drum and a cleaning mechanism for cleaning it. An access opening is provided for imagewise exposure of a charged surface of the drum to create an electrostatic image on the drum. The electrostatic image is toned through another access opening in the cartridge by one of two toning stations which are rotatable into position opposite the access opening to create a toner image. The toner image is transferred to a receiving sheet fed through a receiving sheet opening into contact with the drum. The receiving sheet is separated from the drum by a special mechanism which is part of the cartridge and fed outside of the cartridge to a fusing device.
U.S. Pat. No. 4,591,258, to Nishino et al, issued May 27, 1986, shows a cartridge containing a rotatable photoconductive drum with charging, cleaning and development stations also within the cartridge. An access opening to the drum permits transfer of toner images to a receiving sheet fed into engagement with the drum. Rotation of the drum is accomplished by a driving connection at the end of the cartridge which must mate with a drive member in the receiving apparatus. Projections are provided on the cartridge to prevent damage to the cartridge driving connection member from careless handling.
Many other references show such image member cartridges, and they are used commercially in personal copiers and laser printers. In general, the photoconductive drum is driven by an end connection to the drum through an end of the cartridge. Mounting of the cartridge in the image forming apparatus requires assuring that the drive connection is effectively made.
U.S. Pat. No. 4,712,906, to Bothner et al, issued Dec. 15, 1987, shows a transfer drum for a color printer. In one embodiment, a series of different color toner images are transferred to a receiving sheet carried by the drum which rotates to repeatably present the receiving sheet to an image member. In another embodiment, the different color toner images are transferred directly to the outside surface of a transfer drum to create a multicolor image on the transfer drum which is subsequently transferred in a single step to a receiving sheet at a position remote from the image member. Other references show an intermediate transfer member in the form of an endless web rather than a drum; see for example, U.S. Pat. No. 4,453,820, Suzuki, issued Jun. 12, 1984.
U.S. Pat. No. 4,821,066, Foote et al, issued Apr. 11, 1989 shows a color printer having a photoconductive web movable through an endless path. A transfer drum controls superposition of color toner images and drives the web through its endless path. Use of the transfer drum to drive the web provides uniformity to the drive and other advantages in a system previously driven by a support roller.